Pacing control method, pacing control apparatus, and medical device

ABSTRACT

Disclosed are a pacing control method, a pacing control apparatus, and a medical device. The pacing control method comprises: obtaining an actual heart rate of a patient; and when the actual heart rate meets a preset low heart rate condition, performing cardiac pacing on the patient by using a preset pacing frequency, the preset low heart rate condition being used for representing that the patient is in a life-critical state. The method takes the patient in the life-critical state where the heart rate is severely too slow or even cardiac arrest occurs as an object needing pacing support, and achieves the effect of timely and effectively pacing to support the life of the patient and the effect of avoiding, to a great extent, unnecessary pacing for the patient and the pain of the patient caused by pacing stimulation, especially cannot trigger pacing to occasional bradycardia, non-severe bradycardia, or transient arrest.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a Continuation-In-Part Application of PCTApplication No. PCT/CN2021/128710 filed on Nov. 4, 2021, which claimsthe priority of Chinese patent application 2020112229214 filed on Nov.5, 2020. The contents of the above patent applications are herebyincorporated by reference herein in its entirety.

TECHNICAL FIELD

The present disclosure relates to the technical field of medicalapparatus, in particular to a pacing control method, a pacing controlapparatus, and a medical device.

BACKGROUND

Real-time monitoring of a patient's heart rate, and performing timelycardiac pacing when the heart rate meets a given pacing condition toavoid too slow heart rate or even asystole (cardiac arrest) is the mostbasic purpose of a cardiac medical device.

Existing pacing control methods are based on a preset low-limit heartrate, that is, pacing is performed on the patient at the same pacingfrequency as the preset low-limit heart rate once the monitoredpatient's heart rate decreases to the preset low-limit heart rate, so asto prevent the patient's heart rate from falling below a given value andkeep the patient's heart rate not less than the preset low-limit heartrate. For example, when the preset low-limit heart rate is set to 45bpm, once the monitored patient's heart rate (one heartbeat or R-Rinterval) is less than 45 bpm, pacing is performed on the patient byusing a pacing frequency of 45 bpm so that the R-R interval of thepatient's heart rate will be no longer than the R-R interval of 45 bpm.

Such pacing control method is applied to common endocardial/epicardialpacing. However, for example, transcutaneous pacing (electricalstimulation) tends to cause pain, or even unbearable pain to thepatient; however, in the existing pacing control method, pacing isinitiated once the patient's heart rate decreases to the presetlow-limit heart rate as described above, as a result, there is a problemof frequent pacing operations, which causes patients to be in pain fromtime to time due to pacing operations, resulting in a poor userexperience and reducing the patient's use or compliance with medicalapparatus/device.

BRIEF SUMMARY OF THE INVENTION

The technical problem to be solved by the present disclosure is toovercome the defect of frequent pacing in the pacing control method ofthe prior art, which tends to cause the patient to be in pain from timeto time, resulting in a poor use experience. The purpose is to provide apacing control method, a pacing control apparatus, and a medical device.

The present disclosure solves the above technical problem by thefollowing technical solutions:

the present disclosure provides a pacing control method, comprising:

obtaining an actual heart rate of a patient;

determining whether the actual heart rate meets a preset low heart ratecondition, and if so, performing cardiac pacing on the patient by usinga preset pacing frequency; wherein the preset low heart rate conditionis used for representing that the patient is in a life-critical state.

It is no longer for the patient with bradycardia in the sense oftraditional cardiac pacing therapy, but for the patient with severelytoo slow heart rate or even cardiac arrest due to basic or acute heartdisease. The patient in the aforementioned life-critical state is takenas an object needing pacing support, where death is very likely to occurwithout pacing (the patient is in urgent need of help), that is, thepacing operation in the present disclosure is implemented only as a“necessary”/“life-saving” measure.

Specifically, by presetting trigger conditions for the pacing operation,pacing is performed on the patient by using a higher pacing frequencyonly when the pacing is necessary, and the effect of timely andeffective pacing is achieved to support the life of the patient; at thesame time, the effect of avoiding, to a great extent, unnecessary pacingfor the patient during daily use and the pain of the patient caused bypacing stimulation is also achieved, thereby improving the acceptabilityof the user and/or the use experience.

Preferably, the step of determining whether the actual heart rate meetsthe preset low heart rate condition, and if so, performing cardiacpacing on the patient by using the preset pacing frequency comprises:

determining whether the actual heart rate is less than a preset lowheart rate, and if so, performing cardiac pacing on the patient by usingthe preset pacing frequency.

By monitoring the real-time heart rate of the patient, it is determinedthat the patient is in urgent need of help when the real-time heart rateis less than the given preset low heart rate (much less than the presetlow-limit heart rate in the existing pacing control method), that is,only when the heart rate of the patient is very low can cardiac pacingbe triggered for the patient, and the effect of timely and effectivepacing is achieved to support the life of the patient.

Preferably, the step of determining whether the actual heart rate meetsthe preset low heart rate condition, and if so, performing cardiacpacing on the patient by using the preset pacing frequency comprises:

determining whether the actual heart rate is less than the preset lowheart rate, if so, obtaining a duration (that is, a first low heart rateduration) in which the actual heart rate of the patient is serially lessthan the preset low heart rate, and when the first low heart rateduration reaches a preset duration, performing cardiac pacing on thepatient by using the preset pacing frequency.

By real-time monitoring of the patient's real-time heart rate, only whenthe actual heart rate is less than the preset low heart rate and thefirst low heart rate duration of the actual heart rate reaches thepreset low heart rate duration can pacing be triggered, which avoidsunnecessary pacing operations when the patient's heart rate falls belowthe preset low heart rate by chance, and achieves better pacingmonitoring function, which further improves the use experience of theuser while ensuring patient safety.

Preferably, the preset pacing frequency, the preset low heart rate andthe preset low heart rate duration are parameters that can be reset bymedical personnel according to the patient's condition.

Considering that different patients have different physical states anddifferent degrees of acceptance of pacing, in order to enable eachpatient to receive targeted pacing therapy, the preset low heart rate,preset low heart rate duration and preset pacing frequency that aresuitable for each patient are finally determined by comprehensivelyconsidering multiple parameters such as medical history, currentcondition, medication use and pacing needs of each patient in advance,thereby optimizing patient experience while ensuring patient safety.

Preferably, the preset low heart rate is greater than 0 bpm and lessthan or equal to 40 bpm; or, the preset low heart rate is greater thanor equal to 10 bpm and less than or equal to 30 bpm. The preset lowheart rate is much less than the preset low-limit heart rate in theexisting pacing control method.

Preferably, the preset low heart rate duration comprises 2 s to 5 min;or, the preset low heart rate duration comprises 10 s to 60 s.

Preferably, the preset pacing frequency comprises 40 bpm to 80 bpm.

Preferably, during execution of the step of performing cardiac pacing onthe patient by using the preset pacing frequency, the following stepsare executed simultaneously:

obtaining the number of self heartbeats of the patient during a firstpacing time period;

obtaining the total number of heartbeats of the patient during a giventime period;

wherein the total number of heartbeats comprises the number of selfheartbeats and number of pacing heartbeats; and

the given time period comprises the first pacing time period, and aduration corresponding to the given time period is greater than or equalto a duration corresponding to the first pacing time period;

calculating a first ratio of the number of self heartbeats to the totalnumber of heartbeats;

determining whether the first ratio is greater than or equal to a firstgiven threshold, and if the first ratio is greater than or equal to thefirst given threshold, controlling to terminate pacing; if the firstratio is less than the first given threshold, determining whether thefirst ratio is less than or equal to a second given threshold, if thefirst ratio is less than or equal to the second given threshold,continuing to execute the step of performing cardiac pacing on thepatient by using the preset pacing frequency; if the first ratio isgreater than the second given threshold and less than the first giventhreshold, reducing the preset pacing frequency to a first pacingfrequency, and determining whether the first pacing frequency is lessthan a minimum pacing frequency, if not, performing cardiac pacing onthe patient by using the first pacing frequency; and if so, performingcardiac pacing on the patient by using the minimum pacing frequency; forexample, reducing the preset pacing frequency by 10 bpm, and performingcardiac pacing on the patient by using the reduced pacing frequency; ifthe reduced pacing frequency is less than the minimum pacing frequency,performing cardiac pacing on the patient by using the minimum pacingfrequency; wherein the minimum pacing frequency is 40 bpm to 60 bpm,commonly 50 bpm.

Herein, the ratio of the number of self heartbeats to the total numberof heartbeats corresponding to the first given threshold is relativelyhigh, and the ratio of the number of self heartbeats to the total numberof heartbeats corresponding to the second given threshold is relativelylow.

In order to perform pacing control in a timely and effective manner,after performing pacing on the patient by using the preset pacingfrequency for a period of time, the patient's heart rate isre-evaluated. If the self actual heart rate is greater than the presetpacing frequency (which can be regarded as common heart rate) and lastsfor a given duration, for example, 50 bpm or 60 bpm, it indicates thatthe pacing on the patient at the current pacing frequency is effective,so that the patient recovers the self heart rate and is out of alife-critical situation. At this time, the pacing operation on thepatient may be terminated. By terminating the pacing on the patient intime, the effect of minimizing the pain to the patient can be achieved.

If the self actual heart rates are still less than or only a few heartrates are greater than a first preset pacing heart rate, that is, thecommon heart rate (50 bpm to 60 bpm, which can be adjusted by thedoctor), it indicates that the patient's heart rate has notincreased/recovered at the current pacing frequency or theincrease/recovery is not enough to support proper blood circulation. Atthis time, the patient's life safety is further ensured by continuing toperform pacing on the patient.

Preferably, the first given threshold is 50% to 100%, the second giventhreshold is 0 to 30%, and the minimum pacing frequency is 40 bpm to 60bpm.

Preferably, the pacing control method also comprises:

obtaining the number of pacing heartbeats of the patient during thefirst pacing time period;

obtaining the total number of heartbeats of the patient during the giventime period;

wherein the total number of heartbeats comprises the number of selfheartbeats and the number of pacing heartbeats; and

the given time period comprises the first pacing time period, and aduration corresponding to the given time period is greater than or equalto a duration corresponding to the first pacing time period;

calculating a second ratio of the number of pacing heartbeats to thetotal number of heartbeats;

determining whether the second ratio is less than or equal to a thirdgiven threshold, and if the second ratio is less than or equal to thethird given threshold, controlling to terminate pacing; if the secondratio is greater than the third given threshold, determining whether thesecond ratio is greater than or equal to a fourth given threshold, ifthe second ratio is greater than or equal to the fourth given threshold,continuing to execute the step of performing cardiac pacing on thepatient by using the preset pacing frequency; if the second ratio isless than the fourth given threshold and greater than the third giventhreshold, reducing the preset pacing frequency to a first pacingfrequency, and determining whether the first pacing frequency is lessthan a minimum pacing frequency, if not, performing cardiac pacing onthe patient by using the first pacing frequency; and if so, performingcardiac pacing on the patient by using the minimum pacing frequency.

Preferably, the third given threshold is 0 to 50%, the fourth giventhreshold is 70 to 100%, and the minimum pacing frequency is 40 bpm to60 bpm.

The present disclosure also provides a pacing control apparatus,comprising:

a heart rate acquisition module for obtaining an actual heart rate of apatient;

a first determination module for determining whether the actual heartrate meets a preset low heart rate condition, and if so, calling apacing module to perform cardiac pacing on the patient by using a presetpacing frequency; wherein the preset low heart rate condition is usedfor representing that the patient is in a life-critical state.

Preferably, the first determination module is used for determiningwhether the actual heart rate is less than a preset low heart rate, andif so, calling the pacing module to perform cardiac pacing on thepatient by using the preset pacing frequency.

Preferably, the first determination module is used for determiningwhether the actual heart rate is less than the preset low heart rate,and if so, calling a duration acquisition module to obtain a first lowheart rate duration in which heart of the patient beats at the actualheart rate;

the first determination module is also used for calling the pacingmodule to perform cardiac pacing on the patient by using the presetpacing frequency when the first low heart rate duration reaches a presetlow heart rate duration.

Preferably, the preset pacing frequency, the preset low heart rate andthe preset low heart rate duration are parameters that can be resetaccording to the patient's condition.

Preferably, the preset low heart rate is greater than 0 bpm and lessthan or equal to 40 bpm; or, the preset low heart rate is greater thanor equal to 10 bpm and less than or equal to 30 bpm.

Preferably, the preset low heart rate duration comprises 2 s to 5 min;or, the preset low heart rate duration comprises 10 s to 60 s.

Preferably, the preset pacing frequency comprises 40 bpm to 80 bpm.

Preferably, the pacing control apparatus also comprises:

a self-heartbeat number acquisition module for obtaining the number ofself heartbeats of the patient during a first pacing time period;

a total-heartbeat number acquisition module for obtaining the totalnumber of heartbeats of the patient during a given time period;

wherein the given time period comprises the first pacing time period,and a duration corresponding to the given time period is greater than orequal to a duration corresponding to the first pacing time period;

a first ratio calculation module for calculating a first ratio of thenumber of self heartbeats to the total number of heartbeats;

a second determination module for determining whether the first ratio isgreater than or equal to a first given threshold, and if the first ratiois greater than or equal to the first given threshold, controlling toterminate pacing; if the first ratio is less than the first giventhreshold, determining whether the first ratio is less than or equal toa second given threshold, if the first ratio is less than or equal tothe second given threshold, calling a pacing module to perform cardiacpacing on the patient by using the preset pacing frequency; if the firstratio is greater than the second given threshold and less than the firstgiven threshold, calling the pacing module to reduce the preset pacingfrequency to a first pacing frequency, and determining whether the firstpacing frequency is less than a minimum pacing frequency, if not,performing cardiac pacing on the patient by using the first pacingfrequency; and if so, performing cardiac pacing on the patient by usingthe minimum pacing frequency; for example, reducing the preset pacingfrequency by 10 bpm, and performing cardiac pacing on the patient byusing the reduced pacing frequency; if the reduced pacing frequency isless than the minimum pacing frequency, performing cardiac pacing on thepatient by using the minimum pacing frequency; wherein the minimumpacing frequency is 40 bpm to 60 bpm, commonly 50 bpm.

Herein, the ratio of the number of self heartbeats to the total numberof heartbeats corresponding to the first given threshold is relativelyhigh, and the ratio of the number of self heartbeats to the total numberof heartbeats corresponding to the second given threshold is relativelylow.

Preferably, the first given threshold is 50 to 100%, the second giventhreshold is 0 to 30%, and the minimum pacing frequency is 40 bpm to 60bpm.

Preferably, the pacing control apparatus also comprises:

a pacing-heartbeat number acquisition module for obtaining the number ofpacing heartbeats of the patient during the first pacing time period;

a total-heartbeat number acquisition module for obtaining the totalnumber of heartbeats of the patient during the given time period;

wherein the total number of heartbeats comprises the number of selfheartbeats and the number of pacing heartbeats; and

the given time period comprises the first pacing time period, and aduration corresponding to the given time period is greater than or equalto a duration corresponding to the first pacing time period;

a second ratio calculation module for calculating a second ratio of thenumber of pacing heartbeats to the total number of heartbeats;

a third determination module for determining whether the second ratio isless than or equal to a third given threshold, if the second ratio isless than or equal to the third given threshold, controlling toterminate pacing; if the second ratio is greater than the third giventhreshold, determining whether the second ratio is greater than or equalto a fourth given threshold, if the second ratio is greater than orequal to the fourth given threshold, calling the pacing module tocontinue to perform cardiac pacing on the patient by using a presetpacing frequency; if the second ratio is less than the fourth giventhreshold and greater than the third given threshold, calling the pacingmodule to reduce the preset pacing frequency to a first pacingfrequency, and determining whether the first pacing frequency is lessthan the minimum pacing frequency, if not, performing cardiac pacing onthe patient by using the first pacing frequency; and if so, performingcardiac pacing on the patient by using the minimum pacing frequency.

Preferably, the third given threshold is 0 to 50%, the fourth giventhreshold is 70 to 100%, and the minimum pacing frequency is 40 bpm to60 bpm.

The present disclosure also provides a medical device, comprising thepacing control apparatus as described above.

Preferably, the medical device comprises a wearable cardioverterdefibrillator (WCD), an external defibrillator (for example, AED), asubcutaneous implantable cardioverter defibrillator (SICD), or amechanical circulatory support device (MCS).

On the basis of common knowledge in the art, each of the preferredconditions can be combined in any way to obtain each preferredembodiment of the present disclosure.

The positive progressive effect of the present disclosure is that:

the present disclosure is no longer for the patient with bradycardia inthe traditional sense, but takes the patient in the life-critical statewhere the heart rate is severely too slow or even cardiac arrest occursdue to basic or acute heart disease as an object needing pacing support;by presetting the trigger conditions for the pacing operation, pacing isperformed on the patient by using a higher pacing frequency only whenthe pacing is necessary, and the effect of timely and effective pacingis achieved to support the life of the patient, and pacing is terminatedwhen the self heart rate of the patient recovers to a certain level; atthe same time, the effect of avoiding, to a great extent, unnecessarypacing for the patient during daily use and the pain of the patientcaused by pacing stimulation is also achieved, thereby improving theuser's acceptability, compliance and use experience of medicalapparatus.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a first flow chart of a pacing control method according toEmbodiment 1 of the present disclosure.

FIG. 2 is a second flow chart of the pacing control method according toEmbodiment 1 of the present disclosure.

FIG. 3 is a third flow chart of the pacing control method according toEmbodiment 1 of the present disclosure.

FIG. 4 is a first flow chart of a pacing control method according toEmbodiment 2 of the present disclosure.

FIG. 5 is a second flow chart of the pacing control method according toEmbodiment 2 of the present disclosure.

FIG. 6 is a first schematic structural diagram of a pacing controlapparatus according to Embodiment 3 of the present disclosure.

FIG. 7 is a second schematic structural diagram of the pacing controlapparatus according to Embodiment 3 of the present disclosure.

FIG. 8 is a first schematic structural diagram of a pacing controlapparatus according to Embodiment 4 of the present disclosure.

FIG. 9 is a second schematic structural diagram of the pacing controlapparatus according to Embodiment 4 of the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION

The present disclosure is further illustrated below by means ofembodiments, but the present disclosure is not thereby limited to thescope of the embodiments.

Embodiment 1

As shown in FIG. 1 , a pacing control method of the present embodimentcomprises:

S101, obtaining an actual heart rate of a patient;

S102, determining whether the actual heart rate meets a preset low heartrate condition, and if so, performing S103;

S103, performing cardiac pacing on the patient by using a preset pacingfrequency; wherein the preset low heart rate condition is used forrepresenting that the patient is in a life-critical state.

It is no longer for the patient with bradycardia in the traditionalsense, but for the patient with severely too slow heart rate or evencardiac arrest due to basic or acute heart disease. The patient who isin the aforementioned life-critical state is taken as an object needingpacing support, where death is very likely to occur without pacing (thepatient is in urgent need of help), that is, the pacing operation in thepresent disclosure is implemented only as a “necessary”/“life-saving”measure.

Specifically, by presetting the trigger conditions for the pacingoperation, pacing is performed on the patient by using a higher pacingfrequency only when the pacing is necessary, and the effect of timelyand effective pacing is achieved to support the life of the patient; atthe same time, the effect of avoiding, to a great extent, unnecessarypacing for the patient during daily use and the pain of the patientcaused by pacing stimulation is also achieved, thereby improving theuser's acceptability, compliance and use experience of medicalapparatus.

Specifically, as shown in FIG. 2 , step S102 comprises:

S1021, determining whether the actual heart rate is less than a presetlow heart rate, and if so, performing S103.

By monitoring the real-time heart rate of the patient, it is determinedthat the patient is in urgent need of help when the real-time heart rateis less than the given preset low heart rate (much less than the presetlow-limit heart rate in the existing pacing control method), that is,only when the heart rate of the patient is very low can cardiac pacingbe triggered for the patient, and the effect of timely and effectivepacing is achieved to support the life of the patient. Alternatively,

as shown in FIG. 3 , step S102 comprises:

S1022, determining whether the actual heart rate is less than the presetlow heart rate, if so, obtaining a first low heart rate duration inwhich heart of the patient beats at the actual heart rate; anddetermining whether the first low heart rate duration reaches a presetlow heart rate duration, if so, performing S103.

By real-time monitoring of the patient's real-time heart rate, only whenthe actual heart rate is less than the preset low heart rate and thefirst low heart rate duration of the actual heart rate reaches thepreset low heart rate duration can pacing be triggered. For example,when the preset low-limit heart rate is set to 45 bpm, if the monitoredpatient's heart rate (one heartbeat or R-R interval) is less than 45 bpmfor the first time, pacing will not be performed on the patientimmediately, but the next or even subsequent multiple heartbeats or R-Rintervals will be continuously monitored, and when the monitoredpatient's heart rate is serially less than 45 bpm will pacing betriggered. It avoids unnecessary pacing operations when the patient'sheart rate falls below the preset low heart rate by chance, and achievesbetter pacing monitoring function, which further improves the useexperience of the user while ensuring patient safety.

In an embodiment, the preset low heart rate is greater than 0 bpm andless than or equal to 40 bpm, preferably, the preset low heart rateincludes 10 bpm to 30 bpm, and further, the preset low heart rate may beset to 20 bpm. It should be noted that the pacing control method of thepresent embodiment is still applicable when cardiac arrest occurs, thatis, when the real-time heart rate of the patient is 0 bpm, achievingtimely pacing to save the patient's life in an extreme state where thepatient has no heartbeat.

The preset low heart rate duration includes 2 s to 5 min (that is, 2seconds to 5 minutes). The preset low heart rate duration may beadjusted and determined according to the physical states of differentpatients or other actual conditions. The preset low heart rate durationis within the scope of protection of the present disclosure as long asit can be reasonably applied in the technical solutions of the presentdisclosure during the actual pacing process.

In addition, the preset low heart rate duration may also include 2 s to60 s, preferably, the preset low heart rate duration is 2 s to 20 s, andfurther, the preset low heart rate duration may be set to 10 s, and thepreset low heart rate duration may also include 10 s to 60 s.

The preset pacing frequency includes 35 bpm to 90 bpm. The preset pacingfrequency can be adjusted and determined according to the physicalstates of different patients or other actual conditions. The presetpacing frequency is within the scope of protection of the presentdisclosure as long as it can be reasonably applied in the technicalsolutions of the present disclosure during the actual pacing process.

In addition, the preset pacing frequency may also include 40 bpm to 80bpm, preferably, the preset pacing frequency is 50 bpm to 65 bpm.Further, the preset pacing frequency may be set to 60 bpm.

The preset pacing frequency, the preset low heart rate and the presetlow heart rate duration in the present embodiment are parameters thatcan be reset according to the specific conditions of different patients.Considering that there are certain differences in the physical states ofdifferent patients, in order to enable each patient to receive targetedpacing therapy, the preset low heart rate, preset low heart rateduration and preset pacing frequency that are suitable for each patientare finally determined by comprehensively considering multipleparameters such as medical history, current condition, medication useand pacing needs of each patient in advance, thereby optimizing patientexperience while ensuring patient safety.

It should be noted that all parameter values of the present embodimentcan be reset according to actual conditions.

In the present embodiment, for the patient in the life-critical statewhere the heart rate is severely too slow or even cardiac arrest occurs,by presetting the trigger conditions for the pacing operation, pacing isperformed on the patient by using a higher pacing frequency only whenthe pacing is necessary, and the effect of timely and effective pacingis achieved to support the life of the patient, and pacing is terminatedwhen the self heart rate of the patient recovers to a certain level; atthe same time, the effect of avoiding, to a great extent, unnecessarypacing for the patient during daily use and the pain of the patientcaused by pacing stimulation is also achieved, and especially pacing tooccasional bradycardia, non-severe bradycardia, or transient arrestcannot be triggered, thereby improving the user's acceptability,compliance and use experience of medical apparatus.

Embodiment 2

A pacing control method of the present embodiment is a furtherimprovement on Embodiment 1, specifically:

as shown in FIG. 4 , after step S103, the method also comprises:

S104, obtaining the number of self heartbeats of the patient during afirst pacing time period;

wherein the number of heartbeats obtained at this time is the number ofheartbeats on patient's self, that is, the number of non-pacingheartbeats.

S105, obtaining the total number of heartbeats of the patient during agiven time period;

wherein the given time period includes the first pacing time period, andthe duration corresponding to the given time period is greater than orequal to the duration corresponding to the first pacing time period; itis certain that in addition to using time for limitation, the totalnumber of heartbeats may also be used instead of time for limitation(that is, the total number of heartbeats is greater than or equal to thenumber of self heartbeats).

Both the duration corresponding to the first pacing time period and theduration corresponding to the given time period can be set and adjustedaccording to actual needs.

The process of obtaining the number of self heartbeats, the number ofpacing heartbeats and the total number of heartbeats is well establishedin the art and therefore will not be repeated here.

S106, calculating a first ratio of the number of self heartbeats to thetotal number of heartbeats;

S107, determining whether the first ratio is greater than or equal to afirst given threshold, if so, performing step S109; if not, performingstep S108;

S108, determining whether the first ratio is less than or equal to asecond given threshold, if so, continuing to execute step S103; if not,reducing the preset pacing frequency to a first pacing frequency, anddetermining whether the first pacing frequency is less than a minimumpacing frequency, for example, reducing the preset pacing frequency by10 bpm, and performing cardiac pacing on the patient by using thereduced pacing frequency; if not, performing cardiac pacing on thepatient by using the first pacing frequency; if so, performing cardiacpacing on the patient by using the minimum pacing frequency. Herein, theminimum pacing frequency is 40 bpm to 60 bpm, commonly 50 bpm.

Herein, the minimum pacing frequency is a preset pacing threshold, andit is certain that it can be re-determined and adjusted according toactual needs.

The ratio of the number of self heartbeats to the total number ofheartbeats corresponding to the first given threshold is relativelyhigh, and the ratio of the number of self heartbeats to the total numberof heartbeats corresponding to the second given threshold is relativelylow.

Specifically, the first given threshold is 50% to 100%, the second giventhreshold is 0 to 30%, and the minimum pacing frequency is 40 bpm to 60bpm.

Herein, steps S104 to S108 are continuously executed during the pacingprocess until pacing is terminated, so as to perform pacing control astimely and effectively as possible.

S109, controlling to terminate pacing, during which pacing can bemanually terminated or adjusted in real time.

Specifically, the pacing operation may be programmed to last for a givenduration, for example, one minute (from several seconds to severalminutes, specifically, it can be set and adjusted according to actualneeds; in addition, the pacing operation may be manually terminated by aprogrammable controller, an operation button or other means according toactual needs), and the number of self heartbeats of the patient and thetotal number of heartbeats during this time period are accumulated, thenthe ratio of the number of self heartbeats to the total number ofheartbeats of the patient during the pacing phase is calculated; if theratio is greater than a certain given value (50 to 100%, preferably forexample 90%, programmable), it indicates that the pacing is effectiveand the self heart rate has recovered to a level higher than the presetpacing frequency, so it is determined that the pacing can be terminated;if the ratio is less than a certain given value (0 to 30%, preferablyfor example 10%, programmable), it indicates that the patient'sautonomic heart rate has not recovered and pacing support is stillneeded, so pacing is continued using the preset pacing frequency.Otherwise, the pacing frequency is reduced by 10 bpm for pacing, and theabove process continues until the pacing frequency reaches the defaultminimum pacing frequency (in the range of 40 bpm to 60 bpm, preferablyfor example 50 bpm).

In another embodiment, as shown in FIG. 5 , after step S103, the methodalso comprises:

S1010, obtaining the number of pacing heartbeats of the patient duringthe first pacing time period;

S1011, obtaining the total number of heartbeats of the patient duringthe given time period;

wherein the total number of heartbeats includes the number of selfheartbeats and the number of pacing heartbeats;

the given time period includes the first pacing time period, and theduration corresponding to the given time period is greater than or equalto the duration corresponding to the first pacing time period;

S1012, calculating a second ratio of the number of pacing heartbeats tothe total number of heartbeats;

S1013, determining whether the second ratio is less than or equal to athird given threshold, if the second ratio is less than or equal to thethird given threshold, controlling to execute step S1015; if the secondratio is greater than the third given threshold, executing step S1014;

S1014, determining whether the second ratio is greater than or equal toa fourth given threshold, if the second ratio is greater than or equalto the fourth given threshold, continuing to execute step S103; if thesecond ratio is less than the fourth given threshold and greater thanthe third given threshold, reducing the preset pacing frequency to thefirst pacing frequency, and determining whether the first pacingfrequency is less than the minimum pacing frequency, if not, performingcardiac pacing on the patient by using the first pacing frequency; andif so, performing cardiac pacing on the patient by using the minimumpacing frequency.

Herein, the third given threshold is 0 to 50%, the fourth giventhreshold is 70 to 100%, and the minimum pacing frequency is 40 bpm to60 bpm.

Herein, steps S1010 to S1014 are continuously executed during the pacingprocess until pacing is terminated, so as to perform pacing control astimely and effectively as possible.

S1015, controlling to terminate pacing, during which pacing may bemanually terminated or adjusted in real time.

In order to perform pacing control in a timely and effective manner, theself heart rate of the patient is collected when performing pacing onthe patient by using the preset pacing frequency, and after a period oftime, the self heart rate of the patient is re-evaluated. If the selfactual heart rate is greater than the preset pacing frequency (which maybe regarded as common heart rate) and lasts for a given duration, forexample, 50 bpm or 60 bpm, it indicates that the pacing on the patientat the current pacing frequency is effective, so that the patientrecovers the self heart rate and is out of a life-critical situation. Atthis time, the pacing operation on the patient may be terminated. Byterminating the pacing on the patient in time, the effect of minimizingthe pain to the patient can be achieved.

If the self actual heart rates are less than or only a few heart ratesare greater than the first preset pacing heart rate, that is, the commonheart rate (50 bpm to 60 bpm, which can be adjusted by the doctor), itindicates that the patient's heart rate has not increased/recovered atthe current pacing frequency or the increase/recovery is not enough tosupport proper blood circulation. At this time, the patient's lifesafety is further ensured by continuing to perform pacing on thepatient.

It is certain that the above values can be preset or adjusted accordingto the doctor's clinical judgment, so as to adapt to different patientsand meet the needs of different patients, further improving the useexperience of the user.

It should be noted that all parameter values of the present embodimentmay be reset according to actual conditions.

In the present embodiment, for the patient in the life-critical statewhere the heart rate is severely too slow or even cardiac arrest occurs,by presetting the trigger conditions for the pacing operation, pacing isperformed on the patient by using a higher pacing frequency only whenthe pacing is necessary, and the effect of timely and effective pacingis achieved to support the life of the patient, and pacing is terminatedwhen the self heart rate of the patient recovers to a certain level; atthe same time, the effect of avoiding, to a great extent, unnecessarypacing for the patient during daily use and the pain of the patientcaused by pacing stimulation is also achieved, and especially pacing tooccasional bradycardia, non-severe bradycardia, or transient arrestcannot be triggered, thereby improving the user's acceptability,compliance and use experience of medical apparatus. In addition, afterthe pacing operation is implemented, the effectiveness of the pacingoperation on the patient is monitored in a timely manner, and the pacingfrequency is adaptively adjusted to ensure timely and effectiveventricular capture, guaranteeing the patient's life safety.

Embodiment 3

As shown in FIG. 6 , a pacing control apparatus of the presentembodiment comprises a heart rate acquisition module 1, a determinationmodule 2 and a pacing module 3.

The heart rate acquisition module 1 is used for obtaining an actualheart rate of a patient;

the determination module 2 is used for determining whether the actualheart rate meets a preset low heart rate condition, and if so, callingthe pacing module 3 to perform cardiac pacing on the patient by using apreset pacing frequency; wherein the preset low heart rate condition isused for representing that the patient is in a life-critical state.

It is no longer for the patient with bradycardia in the traditionalsense, but for the patient with severely too slow heart rate or evencardiac arrest. The patient who is in the aforementioned life-criticalstate is taken as an object needing pacing support, where death is verylikely to occur without pacing (the patient is in urgent need of help),that is, the pacing operation in the present disclosure is implementedonly as a “necessary”/“life-saving” measure.

Specifically, by presetting the trigger conditions for the pacingoperation, pacing is performed on the patient by using a higher pacingfrequency only when the pacing is necessary, and the effect of timelyand effective pacing is achieved to support the life of the patient; atthe same time, the effect of avoiding, to a great extent, unnecessarypacing for the patient during daily use and the pain of the patientcaused by pacing stimulation is also achieved, and especially pacing tooccasional bradycardia, non-severe bradycardia, or transient arrestcannot be triggered, thereby improving the user's acceptability,compliance and use experience of medical apparatus.

Specifically, the determination module 2 is used for determining whetherthe actual heart rate is less than a preset low heart rate, and if so,calling the pacing module 3 to perform cardiac pacing on the patient byusing the preset pacing frequency.

By monitoring the real-time heart rate of the patient, it is determinedthat the patient is in urgent need of help when the real-time heart rateis less than the given preset low heart rate (much less than the presetlow-limit heart rate in the existing pacing control method), that is,only when the heart rate of the patient is very low can cardiac pacingbe triggered for the patient, and the effect of timely and effectivepacing is achieved to support the life of the patient. Alternatively,

as shown in FIG. 7 , the pacing control apparatus of the presentembodiment also comprises a duration acquisition module 4.

The determination module 2 is used for determining whether the actualheart rate is less than the preset low heart rate, and if so, callingthe duration acquisition module 4 to obtain a first low heart rateduration in which heart of the patient beats at the actual heart rate;

the determination module 2 is also used for calling the pacing module 3to perform cardiac pacing on the patient by using the preset pacingfrequency when the first low heart rate duration reaches a preset lowheart rate duration.

By real-time monitoring of the patient's real-time heart rate, only whenthe actual heart rate is less than the preset low heart rate and thefirst low heart rate duration of the actual heart rate reaches orexceeds the preset low heart rate duration can pacing be triggered,which avoids unnecessary pacing operations when the patient's heart ratefalls below the preset low heart rate by chance, and achieves betterpacing monitoring function, which further improves the use experience ofthe user while ensuring patient safety.

In an embodiment, the preset low heart rate is greater than 0 bpm andless than or equal to 40 bpm, the preset low heart rate is much lessthan the preset low-limit heart rate in the existing pacing controlmethod, and the preset low heart rate can be set to ensure ventricularcapture of the patient after the pacing process. Preferably, the presetlow heart rate includes 10 bpm to 30 bpm, and further, the preset lowheart rate may be set to 20 bpm.

The preset low heart rate duration includes 2 s to 5 min (that is, 2seconds to 5 minutes). The preset low heart rate duration can beadjusted and determined according to the physical states of differentpatients or other actual conditions. The preset low heart rate durationis within the scope of protection of the present disclosure as long asit can be reasonably applied in the technical solutions of the presentdisclosure during the actual pacing process. It should be noted that thepacing control method of the present embodiment is still applicable whencardiac arrest occurs, that is, when the real-time heart rate of thepatient is 0 bpm, achieving timely pacing to save the patient's life inan extreme state where the patient has no heartbeat.

The preset low heart rate duration may include 2 s to 60 s, preferably,the preset low heart rate duration is 2 s to 20 s, and further, thepreset low heart rate duration may be set to 10 s, and the preset lowheart rate duration may also include 10 s to 60 s.

The preset pacing frequency includes 35 bpm to 90 bpm. The preset pacingfrequency may be adjusted and determined according to the physicalstates of different patients or other actual conditions. The presetpacing frequency is within the scope of protection of the presentdisclosure as long as it can be reasonably applied in the technicalsolutions of the present disclosure during the actual pacing process.

In addition, the preset pacing frequency may also include 40 bpm to 80bpm, preferably, the preset pacing frequency is 50 bpm to 65 bpm.Further, the preset pacing frequency may be set to 60 bpm.

The preset pacing frequency, the preset low heart rate and the presetlow heart rate duration of the present embodiment are parameters thatcan be reset according to the specific conditions of different patients.Considering that there are certain differences in the physical states ofdifferent patients, in order to enable each patient to receive targetedpacing therapy, the preset low heart rate, preset low heart rateduration and preset pacing frequency that are suitable for each patientare finally determined by comprehensively considering multipleparameters such as medical history, current condition, medication useand pacing needs of each patient in advance, thereby optimizing patientexperience while ensuring patient safety.

It should be noted that all parameter values of the present embodimentcan be reset according to actual conditions.

In the present embodiment, for the patient in the life-critical statewhere the heart rate is severely too slow or even cardiac arrest occurs,by presetting the trigger conditions for the pacing operation, pacing isperformed on the patient by using a higher pacing frequency only whenthe pacing is necessary, and the effect of timely and effective pacingis achieved to support the life of the patient, and pacing is terminatedwhen the self heart rate of the patient recovers to a certain level; atthe same time, the effect of avoiding, to a great extent, unnecessarypacing for the patient during daily use and the pain of the patientcaused by pacing stimulation is also achieved, and especially pacing tooccasional bradycardia, non-severe bradycardia, or transient arrestcannot be triggered, thereby improving the user's acceptability,compliance and use experience of medical apparatus.

Embodiment 4

A pacing control apparatus of the present embodiment is a furtherimprovement on Embodiment 3, specifically:

as shown in FIG. 8 , the pacing control apparatus of the presentembodiment comprises a self-heartbeat number acquisition module 5, atotal-heartbeat number acquisition module 6, a first ratio calculationmodule 7 and a second determination module 8.

The self-heartbeat number acquisition module 5 is used for obtaining thenumber of self heartbeats of the patient during a first pacing timeperiod;

the total-heartbeat number acquisition module 6 is used for obtainingthe total number of heartbeats of the patient during a given timeperiod;

wherein the total number of heartbeats includes the number of selfheartbeats and the number of pacing heartbeats;

the given time period includes the first pacing time period, and theduration corresponding to the given time period is greater than or equalto the duration corresponding to the first pacing time period;

the first ratio calculation module 7 is used for calculating a firstratio of the number of self heartbeats to the total number ofheartbeats;

the second determination module 8 is used for determining whether thefirst ratio is greater than or equal to a first given threshold, if thefirst ratio is greater than or equal to a first given threshold, callingthe pacing module 3 to control to terminate pacing; if the first ratiois less than the first given threshold, determining whether the firstratio is less than or equal to a second given threshold, if the firstratio is less than or equal to the second given threshold, calling thepacing module 3 to continue to perform cardiac pacing on the patient; ifthe first ratio is greater than or equal to the second given thresholdand less than or equal to the first given threshold, calling the pacingmodule 3 to reduce the preset pacing frequency to a first pacingfrequency, and determining whether the first pacing frequency is lessthan a minimum pacing frequency, for example, reducing the preset pacingfrequency by 10 bpm, and performing cardiac pacing on the patient byusing the reduced pacing frequency; if not, performing cardiac pacing onthe patient by using the first pacing frequency; if so, performingcardiac pacing on the patient by using the minimum pacing frequency.Herein, the minimum pacing frequency is 40 bpm to 60 bpm, commonly 50bpm.

Herein, the minimum pacing frequency is a preset pacing threshold, andit is certain that it may be re-determined and adjusted according toactual needs.

The ratio of the number of self heartbeats to the total number ofheartbeats corresponding to the first given threshold is relativelyhigh, and the ratio of the number of self heartbeats to the total numberof heartbeats corresponding to the second given threshold is relativelylow.

Specifically, the first given threshold is 50 to 100%, the second giventhreshold is 0 to 30%, and the minimum pacing frequency is 40 bpm to 60bpm.

The pacing operation may be programmed to last for a given duration, forexample, one minute (from several seconds to several minutes,specifically, the given duration can be set and adjusted according toactual needs; in addition, the pacing operation may be manuallyterminated by a programmable controller, an operation button or othermeans according to actual needs), and the number of self heartbeats ofthe patient and the total number of heartbeats during the time periodare accumulated, then the ratio of the number of self heartbeats to thetotal number of heartbeats of the patient during the pacing phase iscalculated; if the ratio is greater than a certain given value (50 to100%, preferably for example 90%, programmable), it indicates that thepacing is effective and the self heart rate has recovered to a levelhigher than the preset pacing frequency, so it is determined that thepacing may be terminated; if the ratio is less than a given value (0 to30%, preferably for example 10%, programmable), it indicates that thepatient's autonomic heart rate has not recovered and pacing support isstill needed, so pacing is continued using the preset pacing frequency.Otherwise, the pacing frequency is reduced by 10 bpm for pacing, and theabove process continues until the pacing frequency reaches the defaultminimum pacing frequency (in the range of 40 bpm to 60 bpm, preferablyfor example 50 bpm).

As shown in FIG. 9 , the pacing control apparatus of the presentembodiment also comprises:

a pacing-heartbeat number acquisition module 9 for obtaining the numberof pacing heartbeats of the patient during the first pacing time period;

the total-heartbeat number acquisition module 6 for obtaining the totalnumber of heartbeats of the patient during the given time period;

wherein the total number of heartbeats includes the number of selfheartbeats and the number of pacing heartbeats;

the given time period includes the first pacing time period, and theduration corresponding to the given time period is greater than or equalto the duration corresponding to the first pacing time period;

a second ratio calculation module 10 for calculating a second ratio ofthe number of pacing heartbeats to the total number of heartbeats;

a third determination module 11 for determining whether the second ratiois less than or equal to a third given threshold, if the second ratio isless than or equal to the third given threshold, controlling toterminate pacing; if the second ratio is greater than the third giventhreshold, determining whether the second ratio is greater than or equalto a fourth given threshold, if the second ratio is greater than orequal to the fourth given threshold, calling the pacing module 3 tocontinue to perform cardiac pacing on the patient by using the presetpacing frequency; if the second ratio is less than the fourth giventhreshold and greater than the third given threshold, calling the pacingmodule 3 to reduce the preset pacing frequency to the first pacingfrequency, and determining whether the first pacing frequency is lessthan the minimum pacing frequency, if not, performing cardiac pacing onthe patient by using the first pacing frequency; and if so, performingcardiac pacing on the patient by using the minimum pacing frequency.

Herein, the third given threshold is 0 to 50%, the fourth giventhreshold is 70 to 100%, and the minimum pacing frequency is 40 bpm to60 bpm.

In order to perform pacing control in a timely and effective manner, theself heart rate of the patient is collected when performing pacing onthe patient by using the preset pacing frequency, and after a period oftime, the self heart rate of the patient is re-evaluated. If the selfactual heart rate is greater than the preset pacing frequency (which maybe regarded as common heart rate) and lasts for a given duration, forexample, 50 bpm or 60 bpm, it indicates that the pacing on the patientat the current pacing frequency is effective, so that the patientrecovers the self heart rate and is out of a life-critical situation. Atthis time, the pacing operation on the patient may be terminated. Byterminating the pacing on the patient in time, the effect of minimizingthe pain to the patient can be achieved.

If the self actual heart rates are less than or only a few heart ratesare greater than the first preset pacing heart rate, that is, the commonheart rate (50 bpm to 60 bpm, which can be adjusted by the doctor), itindicates that the patient's heart rate has not increased/recovered atthe current pacing frequency or the increase/recovery is not enough tosupport proper blood circulation. At this time, the patient's lifesafety is further ensured by continuing to perform pacing on thepatient.

It is certain that the above values may be preset or adjusted accordingto the doctor's clinical judgment, so as to adapt to different patientsand meet the needs of different patients, further improving the useexperience of the user.

It should be noted that all parameter values of the present embodimentmay be reset according to actual conditions.

In the present embodiment, for the patient in the life-critical statewhere the heart rate is severely too slow or even cardiac arrest occurs,by presetting the trigger conditions for the pacing operation, pacing isperformed on the patient by using a higher pacing frequency only whenthe pacing is necessary, and the effect of timely and effective pacingis achieved to support the life of the patient, and pacing is terminatedwhen the self heart rate of the patient recovers to a certain level; atthe same time, the effect of avoiding, to a great extent, unnecessarypacing for the patient during daily use and the pain of the patientcaused by pacing stimulation is also achieved, thereby improving theuser's acceptability, compliance and use experience of medicalapparatus. In addition, after the pacing operation is implemented, theeffectiveness of the pacing operation on the patient is monitored in atimely manner, and the pacing frequency is adaptively adjusted to ensuretimely and effective ventricular capture, guaranteeing the patient'slife safety.

Embodiment 5

A medical device of the present embodiment comprises the pacing controlapparatus of Embodiment 3 or 4.

Herein, the medical device includes but is not limited to a wearablecardioverter defibrillator (WCD), an external defibrillator (forexample, AED), a subcutaneous implantable cardioverter defibrillator(SICD), a mechanical circulatory support device (MCS), or other lifesupport apparatuses/devices.

Hardware components, circuit structures and the like required for theabove pacing control process are all existing structures in the wearablecardioverter defibrillator (WCD), external defibrillator, subcutaneousimplantable cardioverter defibrillator (SICD) or mechanical circulatorysupport device (MCS), that is, how the components work together and howthe circuit structures achieve the corresponding functions are wellestablished in the art and therefore will not be repeated here.

The medical device of the present embodiment adopts the above pacingcontrol apparatus, mainly for the patient in the life-critical statewhere the heart rate is severely too slow or even cardiac arrest occurs.When the patient's heart rate continues to be less than the very lowpreset low heart rate for a period of time, it is determined that thepatient needs pacing and it is necessary to perform pacing on thepatient, so pacing is performed on the patient by using a higher pacingfrequency, and the effect of timely and effective pacing is achieved tosupport the life of the patient; at the same time, the effect ofavoiding, to a great extent, unnecessary pacing for the patient duringdaily use and the pain of the patient caused by pacing stimulation isalso achieved, and especially pacing to occasional bradycardia,non-severe bradycardia, or transient arrest cannot be triggered, therebyimproving the user's acceptability, compliance and use experience ofmedical apparatus.

Although the specific embodiments of the present disclosure have beendescribed above, it should be understood by those skilled in the artthat these are merely illustrative examples and that a variety ofchanges or modifications can be made to these embodiments withoutdeparting from the principles and essence of the present disclosure.Therefore, the scope of protection of the present disclosure is limitedby the appended claims.

What is claimed is:
 1. A pacing control method, comprising: obtaining anactual heart rate of a patient; determining whether the actual heartrate meets a preset low heart rate condition, and if so, performingcardiac pacing on the patient by using a preset pacing frequency;wherein the preset low heart rate condition is used for representingthat the patient is in a life-critical state.
 2. The pacing controlmethod according to claim 1, wherein the step of determining whether theactual heart rate meets the preset low heart rate condition, and if so,performing cardiac pacing on the patient by using the preset pacingfrequency comprises: determining whether the actual heart rate is lessthan the preset low heart rate, if so, obtaining a first low heart rateduration in which heart of the patient beats at the actual heart rate,and when the first low heart rate duration reaches a preset low heartrate duration, performing cardiac pacing on the patient by using thepreset pacing frequency.
 3. The pacing control method according to claim2, wherein the preset pacing frequency, the preset low heart rate andthe preset low heart rate duration are parameters that can be resetaccording to the patient's condition.
 4. The pacing control methodaccording to claim 2, wherein the preset low heart rate is greater than0 bpm and less than or equal to 40 bpm; or, the preset low heart rate isgreater than or equal to 10 bpm and less than or equal to 30 bpm.
 5. Thepacing control method according to claim 2, wherein the preset low heartrate duration comprises 2 s to 5 min; or, the preset low heart rateduration comprises 10 s to 60 s.
 6. The pacing control method accordingto claim 1, wherein the preset pacing frequency comprises 40 bpm to 80bpm.
 7. The pacing control method according to claim 1, wherein duringexecution of the step of performing cardiac pacing on the patient byusing the preset pacing frequency, the following steps are executedsimultaneously: obtaining the number of self heartbeats of the patientduring a first pacing time period; obtaining the total number ofheartbeats of the patient during a given time period; wherein the totalnumber of heartbeats comprises the number of self heartbeats and numberof pacing heartbeats; and the given time period comprises the firstpacing time period, and a duration corresponding to the given timeperiod is greater than or equal to a duration corresponding to the firstpacing time period; calculating a first ratio of the number of selfheartbeats to the total number of heartbeats; determining whether thefirst ratio is greater than or equal to a first given threshold, and ifthe first ratio is greater than or equal to the first given threshold,controlling to terminate pacing; if the first ratio is less than thefirst given threshold, determining whether the first ratio is less thanor equal to a second given threshold, if the first ratio is less than orequal to the second given threshold, continuing to execute the step ofperforming cardiac pacing on the patient by using the preset pacingfrequency; if the first ratio is greater than the second given thresholdand less than the first given threshold, reducing the preset pacingfrequency to a first pacing frequency, and determining whether the firstpacing frequency is less than a minimum pacing frequency, if not,performing cardiac pacing on the patient by using the first pacingfrequency; and if so, performing cardiac pacing on the patient by usingthe minimum pacing frequency.
 8. The pacing control method according toclaim 7, wherein the first given threshold is 50% to 100%, the secondgiven threshold is 0 to 30%, and the minimum pacing frequency is 40 bpmto 60 bpm.
 9. The pacing control method according to claim 1, whereinthe pacing control method also comprises: obtaining the number of pacingheartbeats of the patient during a first pacing time period; obtainingthe total number of heartbeats of the patient during a given timeperiod; wherein the total number of heartbeats comprises the number ofself heartbeats and the number of pacing heartbeats; the given timeperiod comprises the first pacing time period, and a durationcorresponding to the given time period is greater than or equal to aduration corresponding to the first pacing time period; calculating asecond ratio of the number of pacing heartbeats to the total number ofheartbeats; determining whether the second ratio is less than or equalto a third given threshold, and if the second ratio is less than orequal to the third given threshold, controlling to terminate pacing; ifthe second ratio is greater than the third given threshold, determiningwhether the second ratio is greater than or equal to a fourth giventhreshold, if the second ratio is greater than or equal to the fourthgiven threshold, continuing to execute the step of performing cardiacpacing on the patient by using the preset pacing frequency; if thesecond ratio is less than the fourth given threshold and greater thanthe third given threshold, reducing the preset pacing frequency to afirst pacing frequency, and determining whether the first pacingfrequency is less than a minimum pacing frequency, if not, performingcardiac pacing on the patient by using the first pacing frequency; andif so, performing cardiac pacing on the patient by using the minimumpacing frequency.
 10. The pacing control method according to claim 9,wherein the third given threshold is 0 to 50%, the fourth giventhreshold is 70 to 100%, and the minimum pacing frequency is 40 bpm to60 bpm.
 11. A pacing control apparatus, comprising: a heart rateacquisition module for obtaining an actual heart rate of a patient; afirst determination module for determining whether the actual heart ratemeets a preset low heart rate condition, and if so, calling a pacingmodule to perform cardiac pacing on the patient by using a preset pacingfrequency; wherein the preset low heart rate condition is used forrepresenting that the patient is in a life-critical state.
 12. Thepacing control apparatus according to claim 11, wherein the firstdetermination module is used for determining whether the actual heartrate is less than the preset low heart rate, and if so, calling aduration acquisition module to obtain a first low heart rate duration inwhich heart of the patient beats at the actual heart rate; the firstdetermination module is also used for calling the pacing module toperform cardiac pacing on the patient by using the preset pacingfrequency when the first low heart rate duration reaches a preset lowheart rate duration.
 13. The pacing control apparatus according to claim12, wherein the preset pacing frequency, the preset low heart rate andthe preset low heart rate duration are parameters that can be resetaccording to the patient's condition.
 14. The pacing control apparatusaccording to claim 12, wherein the preset low heart rate is greater than0 bpm and less than or equal to 40 bpm; or, the preset low heart rate isgreater than or equal to 10 bpm and less than or equal to 30 bpm. 15.The pacing control apparatus according to claim 14, wherein the presetlow heart rate duration comprises 2 s to 5 min; or, the preset low heartrate duration comprises 10 s to 60 s.
 16. The pacing control apparatusaccording to claim 11, wherein the preset pacing frequency comprises 40bpm to 80 bpm.
 17. The pacing control apparatus according to claim 11,wherein the pacing control apparatus also comprises: a self-heartbeatnumber acquisition module for obtaining the number of self heartbeats ofthe patient during a first pacing time period; a total-heartbeat numberacquisition module for obtaining the total number of heartbeats of thepatient during a given time period; wherein the given time periodcomprises the first pacing time period, and a duration corresponding tothe given time period is greater than or equal to a durationcorresponding to the first pacing time period; a first ratio calculationmodule for calculating a first ratio of the number of self heartbeats tothe total number of heartbeats; a second determination module fordetermining whether the first ratio is greater than or equal to a firstgiven threshold, and if the first ratio is greater than or equal to thefirst given threshold, controlling to terminate pacing; if the firstratio is less than the first given threshold, determining whether thefirst ratio is less than or equal to a second given threshold, if thefirst ratio is less than or equal to the second given threshold, callingthe pacing module to perform cardiac pacing on the patient by using thepreset pacing frequency; if the first ratio is greater than the secondgiven threshold and less than the first given threshold, calling thepacing module to reduce the preset pacing frequency to a first pacingfrequency, and determining whether the first pacing frequency is lessthan a minimum pacing frequency, if not, performing cardiac pacing onthe patient by using the first pacing frequency; and if so, performingcardiac pacing on the patient by using the minimum pacing frequency. 18.The pacing control apparatus according to claim 17, wherein the firstgiven threshold is 50 to 100%, the second given threshold is 0 to 30%,and the minimum pacing frequency is 40 bpm to 60 bpm.
 19. The pacingcontrol apparatus according to claim 11, wherein the pacing controlapparatus also comprises: a pacing-heartbeat number acquisition modulefor obtaining the number of pacing heartbeats of the patient during afirst pacing time period; a total-heartbeat number acquisition modulefor obtaining the total number of heartbeats of the patient during agiven time period; wherein the total number of heartbeats comprisesnumber of self heartbeats and the number of pacing heartbeats; and thegiven time period comprises the first pacing time period, and a durationcorresponding to the given time period is greater than or equal to aduration corresponding to the first pacing time period; a second ratiocalculation module for calculating a second ratio of the number ofpacing heartbeats to the total number of heartbeats; a thirddetermination module for determining whether the second ratio is lessthan or equal to a third given threshold, if the second ratio is lessthan or equal to the third given threshold, controlling to terminatepacing; if the second ratio is greater than the third given threshold,determining whether the second ratio is greater than or equal to afourth given threshold, if the second ratio is greater than or equal tothe fourth given threshold, calling the pacing module to continue toperform cardiac pacing on the patient by using a preset pacingfrequency; if the second ratio is less than the fourth given thresholdand greater than the third given threshold, calling the pacing module toreduce the preset pacing frequency to a first pacing frequency, anddetermining whether the first pacing frequency is less than a minimumpacing frequency, if not, performing cardiac pacing on the patient byusing the first pacing frequency; and if so, performing cardiac pacingon the patient by using the minimum pacing frequency.
 20. The pacingcontrol apparatus according to claim 18, wherein the third giventhreshold is 0 to 50%, the fourth given threshold is 70 to 100%, and theminimum pacing frequency is 40 bpm to 60 bpm.
 21. A medical device,comprising the pacing control apparatus according to claim
 11. 22. Themedical device according to claim 21, wherein the medical devicecomprises a wearable cardioverter defibrillator (WCD), an externaldefibrillator, a subcutaneous implantable cardioverter defibrillator(SICD), or a mechanical circulatory support device (MCS).